1. Field of the Invention
The present invention relates to novel 7-(.alpha.-hydroxy-substituted pyridylcarboxamido-.alpha.-phenylacetamido)-3-substituted thiomethyl-.DELTA..sup.3 -cephem-4-carboxylic acid derivatives. More particularly, the invention relates to 7-(.alpha.-hydroxy-substituted pyridylcarboxamido-.alpha.-phenylacetamido)-3-substituted thiomethyl-.DELTA..sup.3 -cephem-4-carboxylic acid derivatives shown by general formula V: ##STR1## wherein A represents a 6-membered heterocyclic ring having one sulfur atom or 2 or 3 nitrogen atoms and the remaining being carbon atoms and R.sup.1, R.sup.2 and R.sup.3, which may be the same or different each represents a hydrogen atom, a lower alkyl group, a lower alkylthio group, an amino group, a lower alkanoylamido group, or an oxo group
And the pharmacologically acceptable salts thereof.
2. Description of the Prior Art
A series of cephalosporin derivatives shown by general formula: ##STR2## wherein R' represents a 5- or 6-membered heterocyclic nucleus having in the nucleus 1-4 nitrogen atoms, oxygen atoms, or sulfur atoms
Are disclosed in Belgian Patent No. 776,222. In these cephalosporin derivatives of the above formula are included and the cephalosporin derivatives having a heterocyclic acyl group attached to the amino group of the .alpha.-aminophenylacetamido group at the 7-position as shown by the general formula: ##STR3## wherein R represents a heterocyclic acyl group which may be substituted by a methyl group and R' has the same meaning as in the above indicated general formula.
However, the aforesaid Belgian patent does not disclose NH--R type compounds having a heterocyclic acyl group which may have a methyl group as the aforesaid cephalosporin derivatives. Furthermore, there are neither disclosures nor suggestions regarding the 5- or 6-membered heterocyclic nuclei substituted by an --SH group in the explanation of group R' described in the specification of the Belgian patent.